Tissue transglutaminase antibodies in celiac disease, comparison of an enzyme linked immunosorbent assay and a dot blot assay

Aims. – The purpose of our study is to determine the sensitivity, specificity and predictive values of an enzyme linked immunosorbent assay (ELISA) and a dot blot assay for the detection of IgA class anti-tissue transglutaminase antibodies (IgA-AtTGA) and to compare these results with those of IgA class anti-endomysium antibodies (IgA-AEA), IgA class anti-reticulin antibodies (IgA-ARA) and IgA class anti-gliadin antibodies (IgA-AGA). Patients. – Serum samples from 143 patients (97 children, 46 adults) with untreated celiac disease (CD) confirmed by intestinal biopsy and 74 disease controls (64 children, 10 adults) were studied. Methods. – The anti-tissue transglutaminase antibodies were detected by dot blot assay and an ELISA using guinea pig tissue transglutaminase (gp-tTG) as antigen. The anti-endomysium antibodies were detected by an indirect immunofluorescence technique on cryostat sections of human umbilical cord. The anti-reticulin antibodies were also investigated by indirect immunofluorescence on cryostat sections of kidney, liver and stomach of rat. The anti-gliadin antibodies were determined by an ELISA. Results. – The sensitivity of an ELISA for the detection of anti-tissue transglutaminase antibodies was 86% in children and 87% in adults and the sensitivity of dot blot assay was 57% in children and 54% in adults. The specificity of an ELISA and dot blot for the detection for anti-tissue transglutaminase antibodies was, respectively, 96% and 88% lower than that of anti-endomysium antibodies (100%). The sensitivity of anti-gliadin antibodies was 97% in children and 91% in adults and their specificity was 85%. The sensitivity of anti-reticulin antibodies was 94% in children and 87% in adults. Their specificity was 100%. Conclusions. – The sensitivity and specificity of an ELISA for the detection of anti-tissue transglutaminase antibodies were better than that of dot blot assay. However, this dot blot assay could screen four celiac patients who have not had anti-tissue transglutaminase antibodies by an ELISA. The sensitivity of anti-endomysium antibodies was better than that of anti-tissue transglutaminase antibodies, anti-reticulin antibodies and anti-gliadin antibodies but in children aged less than 2 years, the sensitivity of anti-gliadin antibodies was better than that of anti-tissue transglutaminase antibodies. Objectif. – Notre travail consiste d’une part à déterminer la sensibilité, la spécificité et les valeurs prédictives positive et négat